City M and City N are 352 km apart. At 3.45 p.m., Elijah is travelling at a uniform speed left City M for City N while Brandon set off from City N to City M along the same road at a uniform speed, which was 8 km/h slower than that of Elijah. The two met at 5.45 p.m.
- Find the speed of Elijah.
- If Brandon continued to travel at the same speed, how long would it take for him to reach his destination after the two met? Express your answer in mixed number.
(a)
Time taken for Elijah and Brandon to travel from 3.45 p.m. to 5.45 p.m. = 2 h
Average speed of Elijah and Brandon
= 352 ÷ 2
= 176 km/h
Elijah's speed
= (176 + 8) ÷ 2
= 184 ÷ 2
= 92 km/h
(b)
Brandon's speed
= 92 - 8
= 84 km/h
Distance that Brandon travelled in 2 h
= 2 x 84
= 168 km
Remaining distance that Brandon needed to travel
= 352 - 168
= 184 km
Time that Brandon needed to reach his destination after the two met
= 184 ÷ 84
= 2
1684 = 2
421 h
Answer(s): (a) 92 km/h; (b) 2
421 h